Photographic elements containing polymeric oxidants

ABSTRACT

Nitroxyl-containing polymers are useful as oxidants in photographic elements or film units.

United States Patent Campbell et al.

[4 1 Feb. 25, 1975 PHOTOGRAPHIC ELEMENTS CONTAINING POLYMERIC OXIDANTSInventors: Gerald A. Campbell; Hyman L.

Cohen; Hans G. Ling; lgnazio S. Ponticello, all of Rochester, NY.

Assignee: Eastman Kodak Company, Rochester, N.Y.

Filed: Nov. 2, 1973 Appl. No.: 412,081

References Cited UNITED STATES PATENTS Land 96/76 R Rogers 96/29 DSchranz et al. 96/77 Gompf et al 96/77 Cohen et a1. 96/67 PrimaryExaminer-Norman G. Torchin Assistant Examiner-Edward C. Kimlin Attorney,Agent, or FirmD. M. DeLeo ABSTRACT Nitroxyl-containing polymers areuseful as oxidants in photographic elements or film units.

19 Claims, No Drawings PIIOTOGRAPI-IIC ELEMENTS. CONTAINING POLYMERICOXIDANTS FIELD OF THE INVENTION This invention relates to the art ofphotography and particularly to photographic elements, such as colordiffusion transfer elements, employing oxidizing agents.

BACKGROUND OF THE INVENTION Color diffusion transfer processes generallyinvolve the use of a photographic element comprising a support, at leastone silver halide emulsion and an image dye-providing material which iscontained in or contiguous said layer. After exposure, such aphotographic element is treated with an alkaline processing solution toeffect imagewise discrimination in the element. As is well known in theart, the dye-providing material can be initially immobile or initiallymobile in the processing solution. Upon alkaline processing of aninitially immobile dye-providing material, a mobile dye or dye precursorcan be released imagewise or the material can be imagewise renderedsoluble and thus mobile. If the material is initially mobile, theprocessing solution typically renders the material insoluble (and thusimmobile) in an imagewise fashion. Whether initially mobile or immobile,upon treatment with a processing solution, the dye-providing materialtypicallyis oxidized under alkaline conditions thereby producingimagewise discrimination in the element.

Exemplary of such color diffusion transfer processes are those usingdeveloping agents as disclosed in U.S. Pat. Nos. 2,698,798 and 2,559,643wherein alatent silver halide image is developed with a color developingagent. As development proceeds, the color developing agent reduces theexposed silver halide to metallic silver and the color developing agentwhich is oxidized as a function of development forms an immobile specieswhile the unoxidized color developing agent is free to migrate to areceiving element. After migration, the color developing agent in thereceiver is oxidized. The oxidized developing agent then self-couples orcouples with a color coupler to form apositive dye image.

A more recent example of a photographic process in which oxidationcauses formation of an image dye is described in copending Lestina andBush US. application Ser. No. 308,869, filed Nov. 22, I97 2. andentitled PHOTOGRAPHIC ELEMENTS CONTAINING OX- ICHROMIC COMPOUNDS. Thoseoxichromic compounds are ones which undergo chromogenic oxidation toform a new chromophore. Useful materials of that type are oxichromiccompounds which contain a developing moiety and an oxichromic moiety andhave the general formula D-(OC) wherein D is a group which is a silverhalide developer such as a hydroquinone moiety and C is a moiety whichundergoes chromogenic oxidation to form an image dye. These oxichromiccompounds are particularly useful in an image transfer unit format inwhich the respective initially diffusible oxichromic compounds or theinitially nondiffusible compounds are used in combination with theappropriate silver halide emulsions.

In order to achieve optimum results when using such oxichromiccompounds, it is desirable to have an oxidant which can be easilyincorporated in a photographic element with good stability and whichwill readily oxidize the oxichromic moiety without adversely affectingother ingredients of a given photographic element or film unit. Theoxidative conversion of oxichromic compounds or of other color-providingmaterials is necessary in order to achieve color image formation.Accordingly, there is a continuing need in the art for materials whichexhibit suitable oxidation capability. Copending Chang et al. U.S.application Ser. No. 367,304, filed June 5, 1973 and entitled PHO-TOGRAPl-IIC ELEMENTS CONTAINING OXI- DANTS I, incorporated herein byreference describes the use of a simple nitroxyl free radicals asphotographic oxidants. It would be desirable to provide even less mobilenitroxyl compounds than most of those described by Chang et al. in orderto prevent wandering of the oxidant throughout the photographic element.

Some polymeric nitroxyl group-containing polymers are known in the art.Those having a high nitroxyl radical content are typically waterinsoluble, of low molecular weight, unstable, or a combination of theseundesirable properties. For example, O. H. Griffith, J. F. W. Keana, S.Rottschaefer, and T. A. Warlick, JACS, 89, 5072 (I967) describe thesynthesis and anionic polymerization of monomer I and the reaction of:

copoly(maleic anhydride-methyl vinyl ether) (mole ratio 1:1) with thenitroxyl alcohol II.

3 CH3 3 CH The polymers prepared from monomer I must be polymerized byanionic polymerization techniques which give low molecular weightmaterials. Further, the polymers derived from monomer l are waterinsoluble. The desired polymers prepared from the nitroxyl II may bewater soluble, but they are described as highly colored materials whichsuggests instability. Nitroxyl groupcontaining polymers should show onlythe light red color typical of the nitroxyl radical. The polymersdescribed have nitroxyl groups appended via ester linkages which aretypically less stable than, for example, amide linkages.

V. A. Golubev, Dissertation, University of Moscow (1966) describesthereaction of poly(acryloyl chloride) and nitroxyl II to give insolublecrosslinked polymers which would not be coatable and, therefore, wouldbe unsuitable for photographic purposes.

E. g. Rozantsev and G. F. Pavelko, Vysokomol, Svedin. [B] 9, 866 1967),report the reaction of dialkylbis(l-oxyl-2,2,6,6-tetramethylpiperidine-4-oxyl)silane with sulfurdichloride to give a polymeric product. The polymer is believed to be ahighly branched, water insoluble material.

Nitroxyl groups have been incorporated into various polymers, especiallybiopolymers and proteins, as a label to facilitate analysis byspin-labeling" techniques. In such studies, a-small amount of nitroxylcompound is covalently bonded to the polymer to be studied. The N-O.linkage of the nitroxide possesses an unpaired electron which has acharacteristic ESR spectrum. This spectrum is very sensitive to theenvironment around the N-O. bond and much information can be attainedregarding the conformation of the polymer from changes in the ESRspectrum of the nitroxide. These polymers are designed to have very lownitroxyl group concentrations and the methods used for preparing themrequire tedious handling of hazardous chemicals such as Grignardreagents, nitrosyl chloride, free iodine, lithium metal, and the like.For example, G. Drefahl, H. H. Horhold, and K. D. Hofmann, J. Prdkt.Chem, 37, 137 (1968) describe the treatment of mercurated polystyrenewith nitrosyl chloride, conversion of the resulting nitroso derivativeto the hydroxylamine with a Grignard reagent, and oxidation with silveroxide to produce a nitroxyl polymer containing about one nitroxyiradical per seven repeating styrene units. Likewise, A. T. Bullock, G.G. Cameron, and P. Smith,

Polymer, 89 (1972) labled polystyrene with a t butylnitroxyl group in 4to 6% yield. Similarly, US. Pat. No. 3,453,288 of McConnell relates tothe use of nitroxyls such as III and IV for ESR labeling:

CH3 CH3 N 3 2 CMQCHB CH 3 6' CH3 III Iv None of these prior art polymersappear to be suitable for photographic use because of instability,waterinsolubility, etc, or because of the difficulty in preparing themon a commercial scale. Thus, there is a need in the art for polymericnitroxyl-containing compounds for use in photographic elements.

SUMMARY OF THE INVENTION We have found a class of polymericnitroxylcontaining compounds for use in color diffusion transferelements and in any other photographic element or system which a stablenon-wandering oxidant is a necessary or desirable ingredient.

DESCRIPTION OF PREFERRED EMBODIMENTS The objects of the presentinvention are achieved through the use in photographic elements, e.g., acolor diffusion transfer element, of a class of nitroxylcontainingpolymeric oxidants. Typically, these compounds are used in aphotosensitive element comprising a support having thereon at least onephotographic image recording layer, and at least one layer containing astable free nitroxyl radical of this invention.

As is well knonw in the literature, nitroxyl radicals are compoundscontaining the group which has one unpaired electron. The structure ofthis fragment can be conceived as a superposition of two resonancestructures:

e -b t... 'N' O The contribution of either structure (1) or (2) to theground state may be different, depending on the effects of conjugationand polarity of the medium. Hereinafter, the nitroxyl radicals will berepresented simply by resonance structure (2) without designating theelectron pair associated with the nitrogen atom in accordance withaccepted practice.

The oxidants of this invention are water soluble polymers comprising atleast 40 mole percent of a recurring unit having the formula:

I l R1 n C=O (iuox) wherein:

nis an integer having a value of O or I;

Q represents a bivalent linking group having the formula:

II or -c-1 I-R in which R has the same definition as R and in which thecarbonyl moiety is attached directly to the polymeric backbone;

m and p each represent an integer having a value of Oor l;and

L represents an onium salt group as a phosphonium where R is alkyl ofabout 1 to 10 carbon atoms and X- is an anion), an ammonium salt groupwhere R and X are as defined for phosphonium), including a cyclicammonium salt group (for example,

wherein R is as described above and J represents the atoms necessary tocomplete a 5- or 6-membered heterocyclic ring such as a piperidinium orpiperizinium group), or a sulfonium salt group least 5 mole percent ofrecurring units having appended therefrom a water solubilizing groupsuch as an onium salt group (c.g., ammonium, sulfonium and phosphoniumsalts as described above for L), an acid group including acid saltgroups (e.g., -COOH, -COONa, COONH,,, -SO H, SO Na), and the like.

Suitable nitroxyl radicals useful in this invention include those of theformula:

'-R it- R wherein:

R represents l an alkylene group including substituted alkylene havingabout 1 to l2 carbon atoms, preferably about 3 to 8 carbon atoms, andhaving no hydrogen on the carbon in the ovposition relative to (i.e.,immediatcly adjacent) the nitrogen atom of the formula above or (2) anarylenc group having about 6 to 20 carbon atoms including substitutedarylene having such substituents as alkyl of up to about 10 carbonatoms, alkoxy of up to about 10 carbon atoms, etc; and

R represents 1 an alkyl group including substituted alkyl having about 1to 5 carbon atoms, preferably about 3 to 5 carbon atoms, and having nohydrogen on the carbon atom in the a-position relative to the nitrogenatom or (2) a substituted aryl group having about 6 to carbon atomshaving such substituents as alkyl of up to about 10 carbon atoms, alkoxyof up to about l0 carbon atoms, nitro, etc.

Preferred nitroxyls are those heterocyclic radicals having the formula:

R R", R and R", when taken separately, can each represent a lower alkylgroup having about 1 to 5 carbon atoms;

R and R or R and R can represent an imino group (=NH) includingsubstituted imino (e.g., -NR wherein R is an alkyl group having 1 toabout 25 carbon atoms) or together with the carbon atom to which theyare attached, can represent the carbon atoms necessary to form a 5- or6-membered cycloalkyl or cycloalkenyl nucleus including correspondingsubstituted 5- or 6-membered cyclic nuclei having from about 5 to 25carbon atoms.

One of R and R, when taken with Z, can represent a double bond in thecyclic nucleus formed by Z, in which case R and R respectively,represents (1) an aryl group having about 6 to 25 carbon atoms,including substituted aryl (e.g., tolyl, aminophenyl,diethylaminophenyl, chlorophenyl, diphenylaminophenyl) or (2) an aminoradical including substituted amino (e.g., dimethylamino,methylethylamino, methylphenylamino); and

Z represents the nonmetallic atoms necessary to complete a 5-, 6- or7-membcred heterocyclic nucleus having up to two nitrogen hetero atomsand including substituted 5-, 6- or 7'membered heterocyclic nucleihaving such substituents as alkyl having 1 to about 25 carbon atoms,aryl having 1 to about 25 carbon atoms including substituted aryl, aminoincluding alkyl and aryl substituted amino, substituted carbonamido,substituted sulfonamido, substituted carbonyloxy, oxo (=0), imino (=NH)including substituted imino (e.g., =NR, where R is alkyl as above),hydroxy, an oxygen atom, and the like.

Various synthetic techniques for preparing nitroxyl radicals useful informing the nitroxyl substituents on the polymers of this invention aredescribed in Free Nitroxyl Radicals, E. G. Rozantsev, Plenum Press, NewYork, 1970. A large number of stable radicals can be prepared fromheterocyclic amines which have no hydrogen on the carbon atoms ato thenitrogen atoms such as di-t-alkylamines, t-alkylarylamines, etc. Thoseamines are oxidized with hydrogen peroxide in the presence of (l)phosphotungstic acid or (2) a salt of vanadium, molybdenum or tungsten.Diarylamines are oxidized to the corresponding diarylnitroxyl withperbenzoic acid at 0C. Heterocyclic nitroxyls having more than oneheteroatom (e.g., porphyrexide are also known in the art as are methodsfor their preparation. Similarly, binitroxyls and conjugated biradicalsare also known. See, for example, Organic Chemistry of Stable FreeRadicals, Forrester et al., 1968.

The term stable as used in connection with the nitroxyl radicals pendentfrom the present polymeric oxidants has reference to the fact that thesecompounds exist as free radicals without self-decomposing for a periodof time extending at least until the imaging process is substantiallycomplete. 7

The nitroxyl-containing polymers of this invention can be colored,provided the coloration of the oxidant does not adversely effect imagequality. In a format wherein the oxidant remains behind an opaque layerwhere it cannot be viewed, the coloration of the oxidant will notinterfere with image quality. Of course,

valent bond (linking the nitroxyl radical to the remainder-of thepolymer) is located in the 4- r para-position relative to the nitrogenatom of Formula (7).

The nitroxyl-containing polymers of this invention colorless or lowcolor nitroxyl-containing polymers, 5 can be prepared by severalmethods. In one embodiwhich at most give rise to only a very low Dmin.,are particularly preferred in that such materials are more versatile. Acolorless or low color oxidant can be positioned in a film unit in anyplace that a colored oxidant ment, a method is employed similar to thatdescribed by Cohen et al. in US. application Ser. No. 400,778, filedSept. 26, 1973 and entitled POLYMERS AND PHOTOGRAPl-IIC ELEMENTSCONTAINING could be located. In addition, a low color oxidant can l0SAME, which application is incorporated herein by refbe positioned, forexample, in an image-receiving element where it is not hidden from view.Because of their greater versatility, polymers containing nitroxylradicals having formula (7) above are particularly preferred wherein:

R R R and R", when taken separately, represent a lower alkyl grouphaving 1 to about 5 carbon atoms;

R and R or R and R together with the carbon atom to which they areattached, represent the carbon atoms necessary to form a 5- or6-membered cycloalkyl Polymer l Polymer 2 represents the carbon atomsnecessary to complete 2 Polymer erence. This method involves thealkylation of a tertiary amine with an alkylating agent. According orthis method a polymer having recurring tertiary amine or alkylatingfunctional groups is reacted with a monofunctional alkylating agent rtertiary amine, respectively, to form an ammonium salt. The presentmethod differs from that of Cohen et al in that the monofunctionalreactant contains a nitroxyl radical as a substituent. This method canbe illustrated as follows:

A. Starting polymer is a tertiary amine o II 1IIHCCH Cl Polltymer O V II(NIOX) R1\lICH CNH-(NIOX) B. Starting polymer is an alkylating agent IINHCCH N(R) V Polymer (NIOX) :69 CIl l\ l-CH Cl:IH

R (NIOX) O NHC N NR -9 Polymer (NIOX) ll cH N NC.II\IH C16 (NIOX) a 5-or 6-membered heterocyclic nucleus including a wherein R is an alkylgroup of about 1 to 10 carbon substituted 5- or 6-membered heterocyclicnucleus having such substituents as alkyl having 1 to about 25 carbonatoms, acyl having 1 to about 25 carbon atoms, amino, substitutedcarbonamido, substituted sulfonamatoms, for example, in both A and B.

Another suitable method for preparing polymers of this inventioninvolves the reaction of a nitroxylido, substituted carbonyloxy, oxo(=0), hydroxy and containing primary amine with a copolymer of maleicthe like. Typically, when the heterocyclic nucleus formed by Z is asubstituted 6-membered ring, the coanhydride to produce an N-substitutedpolyimide in which the substituent is a nitroxyl radical as follows:

(NIOX) In this latter reaction, a sufficient amount of earboxyl groupsremain unreacted so as to impart water solubility to the polymer.

Polymeric oxidants having the recurring units of formula 3 in which n isl and Q is a simple alkylene or arylene can be made from thecorresponding polymeric acid chloride or ester with anitroxyl-containing amine as follows:

Polymer or Polymer IIIH l I an CH CH5 CH (NIOX) C=O 'C=O Cl R Similarly,polymeric oxidants in which Q is a simple carbonyloxyalkyl,carbonyloxyaryl, etc, can be made from the corresponding polymeric acidchloride or acid ester and a nitroxyl-containing amine.

The polymers of the present invention can be homopolymers or copolymers.Suitable copolymers can be comprised of recurring units as describedabove together with recurring units derived from another additionpolymerizable monomer. Representative comonomers include ethylene,styrene, acrylics including acrylic and methacrylic esters (as well asacrylic acids and amides), maleic acid, maleimide, methylvinyl ether,acrylonitrile, phenylacrylate, isopropylacrylate, N-vinyI-Z-pyrrolidone,Z-acetoacetoxyethyl methacrylate, active methylene-containing monomerswhich are hardenable by conventional photographic hardeners (asdescribed, for example, in U.S. Pat. Nos. 3,459,290 and 3,488,708incorporated herein by reference), sulfonated monomers (e.g.,B-acryloyloxypropanc-lsulfonic acid, sodium salt or 3methacryloyloxypropane-l-sulfonic acid, sodium salt), and the like.

Whether a homopolymer or a copolymer is used, the nitroxyl-containingpolymers of this invention should have a relatively high molecularweight, preferably greater than about 5,000. Also, as mentioned above,the nitroxyl-containing recurring units of the polymer should compriseat least 40 mole percent of the total polymer in order to provide goodoxidizing properties. Preferred embodiments of this invention use apolymer of the type described which contains greater than 50 molepercent of the nitroxyl-containing recurring unit. As also mentionedabove, the polymer should contain at least mole percent of recurringunits which have appended a water solubilizing group. The watersolubilizing recurring unit can be the same or different from thenitroxyl-containing recurring unit. Particularly advantageous from thestandpoint of preparation are those polymers in which thewater-solubilizing group is contained in the same recurring unit as thenitroxyl radical.

The nitroxyl-containing polymers described herein can be used in a widevariety of photographic elements or in photographic film units. Incertain embodiments, these polymers can be used in photographic elementsor film units to provide an oxidant for the synthesis of image dyes. Thenitroxyl radicals ofthese polymers can be used to generate oxidizedcolor developing agent which then reacts with a color coupler to formthe image dye. Additionally, these radicals can be used to oxidize acompound directly to an image dye as in the case ofleuco indoanilines,leuco indophenols, leuco triarylmethanes and other dye precursors.

In one embodiment, the present nitroxyl-containing polymers are usefulin color diffusion transfer processes such as those in which unreactedcolor formers in undeveloped or partially developed areas of aphotographic element diffuse im agewise, after color development of theexposed layers, to a receiving layer in which the color formers reactwith oxidized color developer to produce an imagewise distribution ofdye.

Polymer CH2 CH2 C=O NH (NIOX) By including a polymeric oxidant of thisinvention in the receiving layer or having it in association therewith,dyes are formed imagewise in that element as a result of theinterreaction of the oxidant, color developer and diffused color former.Processes of this type are described further in British Pat. No.926,462, dated May 15, I963, incorporated herein by reference.

Examples of processes in which an image is formed upon oxidation oftransferred color developer and color coupler are described in U.S. Pat.Nos. 2,559,293 and 2,698,798, incorporated herein by reference.Similarly, the present oxidants can be used in imaging processes basedon leuco anthraquinones and other dye precursors which produce dyes whenoxidized or processes based on developers which self-couple uponoxidation, thereby producing dyes. Processes of these latter types aredescribed further in U.S. Pat. Nos. 2,892,710 and 2,698,798,respectively, both incorporated herein by reference. Likewise, thedescribed oxidants have utility in color diffusion transfer processesusing a leuco developing agent, as discussed in U.S. Pat. Nos. 2,992,105and 2,909,430, incorporated herein by reference.

In another embodiment, the nitroxyl'containing polymers can be used tooxidize the developer portion of a dye developer (Le, a compound whichcontains a silver halide developing moiety and a separate moiety whichcontains the chromophore of an image dye). The nitroxyl radical selectedmust have an oxidation potential sufficient to oxidize the developerportion of the molecule, such as the hydroquinone portion. In thisembodiment, the nitroxyl radicals on the polymeric oxidant can functionto immobilize the dye developer, such as when it diffuses to thereceiver layer, by forming the quinone, quinonimide, etc, of thedeveloper moiety which is generally quite insoluble in an alkalineprocessing solution.

In other embodiments, the nitroxyl radical can be used to stabilize apreformed image dye. In some embodiments, the nitroxyls produce abeneficial increase in the stability of azo dyes which are transferredto an image-receiving layer.

In still other embodiments, a photographic element containing thepresent oxidants can be treated to form an image-wise distribution ofoxidant. The photographic element can then be contacted with a materialwhich will undergo oxidation to produce an image record in thephotographic element. In one example of this embodiment, a photographicelement bearing a silver halide emulsion and an adjacent layercontaining the present nondiffusible nitroxyl oxidant can be developedwith a silver halide developer. Where silver halide is not developed,the oxidant will be reduced. The element can then be contacted with asolution of color coupler and color developer to react with theremaining imagewise distribution of nitroxyl compound and produce animage dye.

The nitroxyl-containing polymers of this invention are particularly wellsuited for use as oxidants in photographic elements or film units whichcontain an oxichromic compound of the type described in copendingLestina and Bush U.S. application Ser. No. 308,869, mentioned above andincorporated herein by reference. Preferred oxichromic compounds arethose which undergo chromogenic oxidation to form a photographic imagedye. In one embodiment, the present nitroxyl radical oxidants areincorporated into photographic elements containing oxichromic compoundsof the formula:

wherein (COUP) is a photographic color coupler linked to the nitrogenatom through a carbon atom at the coupling position, such as a phenoliccoupler, a pyrazolone coupler, a pyrazolotriazole coupler, couplershaving open-chain ketomethylene groups and the like; Ar is an arylenegroup containing from 6 to 20 carbon atoms, including substituted andunsubstituted arylene groups, fused-ring arylene groups and the like; Jcan be an amino group, including substituted amines, a hydroxyl group orthe group:

ll -O-CR in which R is a group containing from 1 to 12 carbon atoms,which can be alkyl group, an aryl group, including a substituted alkylgroup, a substituted aryl group and the like; R" is a hydrogen atom orthe group:

0 ll -C-R in which R" is as defined above and is preferably apolyhalogenated alkyl group; and T is a group which is (l) a silverhalide developing agent which is preferably an aromatic grouppolysubstituted with hydroxy, amino or substituted amino groups or (2)an oxidizable releasing group (i.e., a group which can be oxidized tofacilitate subsequent release of a group or a group which can beoxidized to prevent the normal release of a group under the processingconditions When T is a silver halide developing agent, the resultantcompound preferably is initially mobile. When T is an oxidizablereleasing group, the resultant compound preferably is initiallyimmobile.

The present nitroxyl oxidants can be used in the processing fluid ifoxidation is desired at this location in a diffusion transfer film unit.More commonly, the present oxidants are located near or in the imagereceiving layer of a diffusion transfer film unit employing other imagedye-providing materials mentioned above. The image-transfer film unitscan be any of those described in the following patents, all incorporatedherein by reference: U.S. Pat. Nos. 2,543,181, 2,983,606, 3,227,550,3,227,552, 3,415,644, 3,415,645, 3,415,646 and 3,635,707, Canadian Pat.No. 674,082, and Belgian Pat. Nos. 757,959 and 757,960, both issued Apr.23, 1971.

When used in the processing fluid of various diffusion transfer filmunits, the nitroxyl oxidant is typically present in a concentration ofabout 0.01 to about 0.1 molar. When not contained in the processingfluid, the present oxidants are coated in at least one layer whichtypically contains a binder such as gelatin, poly( vinyl alcohol), etc.Of course, the nitroxyl-containing polymers described herein can also beone of several ingredients in a given layer. For example, when used incolor diffusion transfer units, the nitroxyl polymers can be containedin a mordant layer. In general, these polymers are coated at a coverageof about 40 to 500 mg/ft depending upon the milliequivalents of nitroxylradical in the polymer of choice. There should, however, be sufficientnitroxyl-containing polymer present to give substantially completeoxidation. The amount necessary to accomplish complete oxidation is, ofcourse, dependent upon the amount and type of oxichromic compound used.In preferred embodiments, the nitroxyl polymers are used inimage-transfer film units which are designed to be processed with asingle processing solution, and the resulting positive image is viewedthrough a transparent support against an opaque background, preferablywhere all of the silver halide recording layers and the image-receivinglayer remain laminated between two dimensionally stable supports afterprocessing.

A suitable image transfer film unit in which the present oxidants areuseful typically comprises:

1. a photosensitive element comprising a support having thereon at leastone layer containing a silver halide emulsion having associatedtherewith an image dyeproviding material and preferably at least threeof said layers wherein one layer contains a blue-sensitive silver halideemulsion, one layer contains a green-sensitive silver halide emulsion,and one layer contains a redsensitive silver halide emulsion;

2. an image-receiving layer which can be located on a separate supportsuperposed or adapted to be superposed on said photosensitive elementor, preferably. it can be positioned in the photosensitive element onthe same support adjacent to the photosensitive silver halide emulsionlayers; and

3. means containing an alkaline processing composition adapted todischarge its contents within said film unit. Where the receiver layeris coated on the same support with the photosensitive silver halidelayers, the support is preferably a transparent support, an opaque layeris preferably positioned between the imagereceiving layer and thephotosensitive silver halide layer, and the alkaline processingcomposition preferably contains an opacifying substance such as carbonor pH-indicator dye which is discharged into the film unit between adimensionally stable support or cover sheet and the photosensitiveelement. In certain embodiments, the cover sheet can be superposed oradapted to be superposed on the photosensitive element. Theimage-receiving layer can be coated on the cover sheet. In certainpreferred embodiments where the imagereceiving layer is located in thephotosensitive element, a neutralizing layer is located on the coversheet.

The means containing the alkaline processing solution can be any meansknown in the art for this purpose, including rupturable containerspositioned at the point of desired discharge of its contents into thefilm unit and adapted to be passed between a pair ofjuxtaposed rollersto effect discharge of the contents into the film unit, frangiblecontainers positioned over within the photosensitive element, hypodermicsyringes, and the like.

The silver halide emulsions useful in our invention are well known tothose skilled in the art and are described in Product Licensing Index,Volume 92, December, 1971, publication 9232, p. 107, paragraph I,

Emulsion types, they may be chemically and spectrally sensitized asdescribed on page 107, paragraph III, Chemical sensitization, and pp.108-109, paragraph XV, Spectral sensitization, of the above article;they can be protected against the production of fog and can bestabilized against loss of sensitivity during keeping by employing thematerials described on p. 107, paragraph V, Antifoggants and stabilizersof the above article; they can contain development modifiers, hardeners,and coating aids asdescribed on pp. 107-108, paragraph IV, Developmentmodifiers, paragraph VII, Hardeners; and paragraph XII, Coating aids ofthe above article; they and other layers in the photographic elementsused in this invention can contain plasticizers, vehicles and filterdyes described on p. 108, paragraph XI, Plasticizers and lubricants, andparagraph VIII, Vehicles, and p. 109, paragraph XVI, Absorbing andfilter dyes, of the above article; they and other layers in thephotographic elements used in this invention may contain addenda whichare incorporated by using the procedures described on p. 109, paragraphXVII, Methods of addition", of the above article; and they can be coatedby using the various techniques described on p. 109, paragraph XVIII,Coating procedures, of the above article, the disclosures of which arehereby incorporated by reference.

Any material can be employed as the image-receiving layer in thisinvention as long as the desired function of mordanting or otherwisefixing the dye images will be obtained. The particular material chosenwill, of course, depend upon the dye to be mordanted. If acid dyes areto be mordanted, the image-receiving layer can contain basic polymericmordants such as polymers of amino guanidine derivatives of vinyl methylketone such as described in Minsk U.S. Pat. No. 2,882,156, issued Apr.14, 1959, and basic polymeric mordants such as described in Cohen et al.U.S. Pat. No. 3,709,690, issued Jan. 9, 1973.

Additional mordants include cationic mordants such as polymericcompounds composed of a polymer having quaternary nitrogen groups and atleast two aromatic nuclei for each quaternary nitrogen in the polymercation (i.e., having at least two aromatic nuclei for each positivelycharged nitrogen atom), such polymeric compounds being substantiallyfree of carboxy groups. Useful mordants of this type are comprised ofunits of the following formula in copolymerized relationship with unitsof at least one other ethylenically unsaturated monomer.

I R X wherein R and R each represent a hydrogen atom or a lower alkylradical (of 1 to about 6 carbon atoms) and R can additionally be a groupcontaining at least one aromatic nucleus (e.g., phenyl, na'phthyl,tolyl); Q' can be a divalent alkylene radical (of l to about 6 carbonatoms), a divalent arylene radical, a divalent aralkylene radical, adivalent arylenealkylene radical,

wherein R is an alkylene radical, or R can be taken together with Q toform a group; R, R and R can be lower alkyl or aryl, or R and R and thenitrogen atom to which they are attached can together with Q representthe atoms and bonds necessary to form a quaternized nitrogencontainingheterocyclic ring, and X is a monovalent negative salt forming radicalor atom in ionic relationship with the positive salt forming radical;wherein said polymer is substantially free of carboxy groups and whereinthe positive salt forming radical of said polymer comprises at least twoaryl groups for each quaternary nitrogen atom in said polymer. Thesepreferred polymeric cationic mordants are described further in theabove-mentioned U.S. Pat. No. 3,709,690, incorporated herein byreference.

Other mordants useful in our invention include poly- 4-vinylpyridine,the 2-vinylpyridine polymer metho-ptoluene sulfonate and similarcompounds described in Sprague et al. U.S. Pat. No. 2,484,430, issuedOct. 11, 1949, and cetyl trimethylammonium bromide, etc. Effectivemordanting compositions are also described in Whitmore U.S. Pat. No.3,271,148 and Bush U.S. Pat. No. 3,271,147, both issued Sept. 6, 1966.Additionally, the present nitroxyl-containing polymers which contain aquaternary amine center can be used as mordants for acid dyes withoutthe need for any other mordants. Thus, many of the polymeric compoundsof this invention can serve both as an oxidant and as a mordant forimage dyes.

The following preparations and examples are included for a furtherunderstanding of the present invention.

PREPARATION l A solution of 3.18 g. (0.0202 mole) of poly(2-dimethylaminoethyl methacrylate [n] benzene 0.40* and 5.0 g. (0.0202mole) of 4-(a-chloroacetamido)-2,2.6,6-tetramethylpiperidine-l-oxyl in30 mLof N,N-dimethylformamide was heated under nitrogen on the steambath for 3 hours. The polymer was isolated by precipitation in ether,collected by filtration, and dissolved in 30 ml. of methanol. Thepolymer was reprecipitated in ether, collected by filtration, anddissolved in 30 ml. of water while still clamp. The solution was thenplaced on the rotary evaporator for a short time to remove traces ofether, leaving an aqueous solution of polymeric oxidant l (18% solids).The theoretical values calculated for C H N O Cl and the values actuallyfound are as follows:

Calculated: C,56.4;H,8.7;N,10.4;C1,8.8

Found: C,56.4;H,8.6;N,10.4;C1,8.2

*All inherent viscosities were measured at 25C. at a concentration of0.25 g/deciliter of solution in the solvent specified.

PREPARATION 2 Preparation 1 was repeated using 3.72 g. (0.0202 mole) ofpoly[N-(3-dimethylamino-l,l-dimethylpropyl)acrylamide] and 5.0-g.(0.0202 mole) of 4-(achloroacetamido )-2 ,2 ,6 ,6-tetramethylpiperidinel oxyl except that the product was isolated by precipitation' fromacetone. The polymer was dissolved in ml. of water to give a clearsolution containing 9.9% solids.

Calculated: Found:

C, 58.4; H C, 54.9; H,

bio

PREPARATION 3 A reaction was carried out with 3.15 g. (0.0202 mole) ofpoly[N-(3-dimethylaminopropyl)acrylamide] [n] 0.28 and 5.0 g. (0.0202mole) of 4-(achloroacetamido)-2,2,6,6-tetramethylpiperidine-1- oxyl inthe same manner as in Preparation 1 except that the product was isolatedfirst by precipitation in acetone, followed by dissolution in 30 ml. ofmethanol and reprecipitation in ether. The polymer was then dissolved in35 ml. of water to give a clear solution containing 19.9% solids. Thetheoretical values calculated for C H ClN O and the values actuallyfound are as follows:

"DMF N,N-Dimethylformamide Calculated: C, 56.4; H, 8.9; N, 13.9; C1, 8.8Found: C, 56.5; H, 9.6; N, 13.8; CI, 8.2

PREPARATION 4 A reaction was run in the same manner as in Preparation 1using 2.62 g. (0.0101 mole) of poly[styrene-co-N-(3-dimethylaminopropy1)acrylamide] (1:1) and 5.0 g. (0.0202 mole) of4-(a-chloroacetamido)-2,2,6,6- tetramethylpiperidine-l-oxyl except thatthe solution was heated on the steam bath for 5 hours. The final productwas dissolved in 30 ml. of water to give a clear solution containing9.9% solids. The theoretical values calculated for C l-l C1N O and thevalues actually found are as follows:

Calculated: C.63.8; H.8.7 Cl,7.0; N, 11.0 Found: C.66.8; H.8.2 Cl,5.3;N, 10.0

*DMF N,N-Dimethylformamide PREPARATION 5 A solution of3.l0 g. (0.0203mole) of poly(vinylbenzyl chloride) ]'q],, 0.42 and 3.0 g. (0.0102 mole)of N-(2-dimethylaminoethyl)-N"(2,2,6,6-tetramethyl-4-piperidine-l-oxyl)urea in 30 ml. of methoxyethanol was heated at 100Cfor 3 hours. The polymer was precipitated in acetone, collected byfiltration, and dissolved in 30 ml. of methanol. The polymer wasreisolated by precipitation in ether, collected by filtration, anddissolved while still damp in 50 ml. of water. The aqueous solution wasplaced on the rotary evaporator for a short time to remove traces ofether leaving an aqueous solution containing 10.8% solids. Thetheoretical values calculated for C H C1 N O and the values actuallyfound are as follows:

Calculated:

Cl. 12.0 Found: C,

PREPARATION 6 for C I-I N O Cl and the values actually found are asfollows:

Calculated: 8.6; N, Found: 8.9; N,

PREPARATION 7 A solution of 6.4 g. (0.025 mole) ofcopoly(styrenevinylbenzylchloride) (1:1) [1 0.75 and 7.0 g. (0.0273mole) of 4-(a-dimethylaminoacetamido)-2,2,6,6-tetramethylpiperidine-l-oxyl in ml. of benzyl alcohol was heatedat 100C under nitrogen for 3 hours. The polymer was isolated byprecipitation in acetone, collected by filtration, and dissolved in 50ml. of methanol. The product was reprecipitated in ether, collected byfiltration, and dissolved while still damp in ml. of water. The solutionwas placed on the rotary evaporator for a short time to remove traces ofether leaving an aqueous solution containing 9.4% solids. Thetheoretical values calculated for C H N O Cl and the values actuallyfound are as follows:

Calculated:

PREPARATION 8 A solution of 3.55 g. (0.029 mole) ofcopoly[ethylenemaleic anhydride] (1:1) and 5.0 g. (0.029 mole) of3-amino-2,2,5,5-tetramethylpyrrolidine-loxyl in 30 ml. ofN,N-dimethylformamide was heated at C for 30 minutes. The polymer wasprecipitated in ether, collected by filtration, and dissolved in 50 ml.of water while still damp. The solution was placed on the rotaryevaporator for a short time to remove traces of ether leaving an aqueoussolution having a 10% solids content. The theoretical values calculatedfor C H N O and the values actually found are as follows:

H, 8.2; N, 9.9 H, 8.8; N, 10.4

PREPARATION 9 A solution of 3.55 g. (0.029 mole) ofcopoly[ethylenemaleic anhydride] (1:1) and 7.0 g. (0.041 mole) of4-amino-2,2,6,6-tetramethylpiperidine-l-oxyl in 35 ml. ofN,N-dimethylformamide was heated at C for 30 minutes. The polymer wasprecipitated in ether, dissolved in 50 ml. of methanol andreprecipitated in ether. The polymer was collected by filtration anddissolved in 80 ml. of water while still damp. The solution was placedon the rotary evaporator for a short time to remove traces of etherleaving an aqueous solution having an 8.6% solids content. Thetheoretical values calculated for C I-1 N 0 and the values actuallyfound are-as follows:

Calculated: C, 60.7; H, 8.4 N, 9 8 Found: C, 58.7; H, 9.2 N, 9 3

EXAMPLE 1 The oxidants listed in Table 1 below were tested as follows: Amatrix element comprised of a transparent film base support having alayer of 125 mg/ft gelatin and 50 mg/ft of oxichromic compound dissolvedin 75 mg/ft of diethyl lauramide is placed in face-to-face contact witha receiver in the presence of an alkaline processing composition betweenthe matrix and the receiver. The receiver was comprised of a transparentfilm base support having on it a first layer of 200 mg/ft of oxidant(prepared according to the Preparation number given) in 100 mg/ft ofgelatin and a second layer (over the first layer) comprising 2000 mg/ftof titanium dioxide in 200 mg/ft of gelatin. The processing compositioncomprised a 7.5% potassium hydroxide solution containing 2.5%hydroxyethyl cellulose thickener. Upon contact of the two elements, theoxichrome migrated from the matrix through the processing compositionand the titanium dioxide layer into the oxidant layer (which was alsothe mordant layer) of the receiver. The oxichrome was oxidized by thenitroxylcontaining polymeric oxidant to the corresponding dye which wasvisible through the transparent support and against the white backgroundof the titanium dioxide layer. The oxichromic compounds, the oxidantsand the color and density of the dye in the receiver are shown in Table1 below. The structures ofthe oxichromic compounds are shown after theexamples.

Table 1 Time of Oxidant of Contact Dye ln Prep. No. Oxichrome (Seconds)Receiver "max l A 60 Yellow 1.3 l B 60 Magenta 1.7 1 C 60 Cyan 1.7 2 D60 Cyan 1.5 2 C 60 Cyan 1.2 2 B 60 Magenta 2.1 2 A 60 Yellow 1.7 3 A 60Yellow 1.4 3 B 60 Magenta 2.2 3 D 60 Cyan 1.5 4 A 60 Yellow 1.5 4 B 60Magenta 2.3 4 D 60 Cyan 1.8 5 A 60 Yellow 1.3 5 B 60 Magenta 2.4 5 D 60Cyan 1.6 6 A 60 Yellow 1.2 6 B 60 Magenta 1.3 6 D 60 Cyan 1.3 7 A 60Yellow 1.5 7 B 60 Magenta 2.1 7 D 60 Cyan 1.5

EXAMPLE 2 The procedure of Example 1 was repeated using the oxidant ofPreparation No. 8. This oxidant does not contain a quaternary aminecenter and thus, between the oxidant layer and the support, there wasinterposed a mordant layer comprised of 200 mg/ft ofcopoly[styrene:N,N-dimethyl-N-benzyl-N(3-maleiimidopropyl- )ammoniumchloride] in 100 mg/ft of gelatin. After contacting the matrix and thereceiver for 60 seconds in the presence of the developing composition,oxichrome A produced a yellow dye having a density of 0.7 and oxichromeB produced a magenta dye having a density of 2.4.

EXAMPLE 3 An integral, color transfer, photographic element is preparedas follows (the full identification of certain components follows theexamples):

1. transparent polyethylene terephthalate support;

2. dye mordant/oxidant layer containing gelatin at 100 mg/ft and thenitroxyl-containing oxidant of Preparation No. 4 at 200 mg/ft 3. layercontaining titanium dioxide at 2000 mg/ft and gelatin at 200 mg/ft;

4. layer containing carbon opacifying agent at 20 mg/ft and gelatin at156 mg/ft 5. layer containing gelatin at mg/ft2,5-disecdodecylhydroquinone at 70 mg/ft and tricresyl phosphate at 23mglft 6. layer containing a red-sensitive silver bromoiodide emulsion at70 mg/ft based on silver, gelatin at 230 mg/ft Compound E at 42 mg/ftdispersed in diethyl lauramide at 73 mg/ft 5-(2-cyanoethylthio)-l-phenyltetrazole at 5 mg/ft dispersed in tricresyl phosphate at 15mg/ft and 5,6,7,8-tetrahydro-5,8- methano-l,4-naphthalenediol at 10mg/ft 7. layer containing gelatin at 300 mglft2,5-disecdodecylhydroquinone at 70 mg/ft and a magenta filte'r dye at 30mg/ft dissolved in diethyl lauramide at 50 mg/ft 8. layer containinggreen-sensitive silver bromoiodide emulsion at 70 mg/ft based on silver,gelatin at 230 mglft oxichromic compound B at 54 mg/ft dispersed indiethyl lauramide at 64 mg/ft 5-(2- cyanoethylthio)-l-phenyltetrazole at5 mg/ft dispersed in tricresyl phosphate and5,6,7,8-tetrahydro-5,8-methano, 1,4-naphthalenediol at 10 mg/ft 9. layercontaining gelatin at 300 mglft 2,5-disecdodecylhydroquinone at 70 mg/ftand a yellow filter dye at mg/ft dispersed in diethyl lauramide at 28mg/ft 10. layer containing a blue-sensitive silver bromoiodide emulsionat 70 mg/ft based on silver, gelatin at 210 mg/ft oxichromic compound Aat 64 mg/ft dispersed in diethyl lauramide at 106 mglft 5-(2-cyanoethylthio)-1-phenyltetrazole at 5 mg/ft dispersed in tricresylphosphate at 15 mg/ft and 5,6,- 7,8-tetrahydro-5 ,S-methano-l,4-naphthalenediol at 10 mg/ft 11. layer containing gelatin at 50 mglftA transparent cover sheet for the above element is prepared as follows:

1. transparent polyethylene terephthalate support;

2. layer containing gelatin at 900 mg/ft, polyacrylic acid at 900 mg/ftand imidazole at 760 mglft 3. layer containing cellulose acetate at 1140mg/ft and copoly(styrene-maleic anhydride) at 60 mg/ft The photographicelement is exposed through a multicolor, graduated-density test object,the transparent cover sheet superposed on the element, and a podcontaining an opaque processing composition is ruptured to dischargebetween the cover sheet and the photosensitive element by passing thefilm unit through juxtaposed rollers having a gap of about 8 mils. Theprocessing composition is as follows:

a-benzylpicolinium bromide The invention has been described in detailwith par- 5,6,7,8-tetrahydro-f ,8-methano- 'ticular reference to certainpreferred embodiments ifl p 3 7 thereof, but it will be understood thatvariations and wateno I met modlficatlons can be effected within thespirit and 5 scope of the invention.

-Continued After about 1 to 2 minutes, a well-defined color image withgood color reproduction is viewed through the We claim:

transparent support of the integral element. 1. A photographic elementcomprising a support hav- Table 2 below gives the structures ofCompounds A ing thereon at least one photosensitive silver saltemulthrough E referred to in the preceding examples. 10 sion layer andat least one layer containing a water- Table 2 Compound Formula 2 I? OCH A (CH C-C-CH-CNH l NH OH E QA OC-CH OH OH mil 2) NHCO (cH h fg B g OHNH Cl Cl 'OQOCH OH I C CO F O F F o (CHQMC NcocF OH X? D Y ?,(CH2MCONHNCOCF3 H c:[ t 01 OH 9 E OH la C.@Y OC5H11 r (cn mcoun or C1 CH Cl 21 22soluble polymer comprising at least 40 mole percent of prising at least40 mole percent of a recurring unit hava recurring unit having theformula: i the formula:

R I i CH c CH -cl l l l R R (o I (3:0 C=O 2 l 2 R-N R N l I (NIOX)(NIOX) l5 wherein:

n is an integer having a value of 0 or 1;

wherein: 0 represents a bivalent llnkmg group of the formula:

n is an integer having a value of 0 or 1; )m )p Q represents a bivalentlinking group of the formula: in which a and 4 each represent analkylene group,

a 4 an arylene group or an alkarylene group, and R can in which R and Reach represent an alkylene group, also represent a group of the formula:

an arylene group or an alkarylene group, and R 'can v 2 also represent agroup of the formula: o O R O 0 2 in which R has the same definition asR and in which 5 or 5 the carbonyl moiety is attached directly to thepolymeric backbone;

m and p each represent an integer having a value of 0 or 1; and in whichR has the same definition as R and in which L represents an Onium lgroup; the carbonyl moiety is attached directly to the poly- Rrepresents h d n atom, a carboxy group or mel'ie backbone? when takentogether with R represents a linking m and p each represent an integerhaving a value of carbonyl group;

0 0r and R 'represents a hydrogen atom, an alkyl group or,

L represents an onium salt group; when taken together i h R a bonylgroup; and

R represents a hydrogen atom of an alkyl group; 40 (NIOX) represents astable free nitroxyl radical;

represents a hydrogen atom a earbexy group or said polymer furthercomprising at least 5 mole percent when taken together with R2represents a linking of a recurring unit having appended therefrom awater carbonyl group; solubilizing group.

R2 represents a hydrogerl atom, an alkyl group, or 6. The film unit asdescribed in claim 5 wherein said when taken together wlth R2 representsa polymer is associated with said image-receiving layer. hohyl group;and 7. The film unit as described in claim 5 wherein said represents aStable free nitroxyl radical; polymer is contained in said alkalineprocessing comsaid polymer further comprising at least 5 mole percent ii Ofa recurring having appended therefrom a water 8. The film unit asdescribed in claim 5 wherein solubilizing P- 5 (NIOX) represents aheterocyclic nitroxyl radical hav- 2. A photographic element asdescribed in claim 1 i the f l wherein (NIOX) represents a heterocyclicnitroxyl radical. ,Z,

3. A photographic element as described in claim 1 lCR 11 wherein n and mare both 1 and L represents an ammo- I R nium salt group.

4. A photographic element as described in claim 1 R E R wherein saidpolymer has a molecular weight greater than about 5000. l

5. A photographic m unit comprising; wherein R R R and R", when takenseparately,

a. a photosensitive element comprising a support each represent a loweralkyl group;

having thereon a photosensitive silver halide emul- R8 ahd Ru R9 and R10represent an hhhle group or, sion having associated therewith an imagedyetogether with the carbon atom to which y are providing compound;attached, represent the carbon atoms necessary to b. an imagedye-receiving layer; and complete a 5- or 6-membered cycloalkyl or cyc.means for discharging an alkaline processing comeloalkehyl nucleus;

i i i hi id fil i oneof R and R, when taken with Z, represents a saidfilm unit containing a water-soluble polymer comdouble bond in thecyclic nucleus formed by Z, in

which case R or R respectively, represents 1) an aryl group or (2) anamino radical; and Z represents the nonmetallic atoms necessary tocomplete a 5-, 6- or 7-membered heterocyclic nucleus. 9. The film unitas described in claim 5 wherein (NIOX) represents a heterocyclicnitroxyl radical having the formula:

wherein:

R R, R and R, when taken separately, represent a lower alkyl group;

R and R or R and R together with the carbon atom to which they areattached, represent the carbon atoms necessary to form a 5- or6-membered cycloalkyl or cycloalkenyl nucleus; and

Z represents the carbon atoms necessary to complete a 5- or 6-memberedheterocyclic nucleus.

10. The film unit as described in claim 5 wherein (NIOX) represents aheterocyclic nitroxyl radical having the formula:

wherein:

R R", R and R each represent a lower alkyl group.

11. A photographic film unit comprising:

a. a photosensitive element comprising a support having thereon a layercontaining a red-sensitive silver halide emulsion having associatedtherewith a cyan image dye-providing material, a layer containing agreen-sensitive silver halide emulsion having associated therewith amagenta image dyeproviding material, and a layer containing abluesensitive silver halide emulsion having associated therewith ayellow image dye-providing material,

b. an image dye-receiving layer; and

c. means for discharging an alkaline processing composition within saidtilm unit;

said film unit containing a water-soluble polymer comprising at least 40mole percent of a recurring unit having the formula:

wherein:

n is an integer having a value of 0 or 1; Q represents a bivalentlinking group of the formula:

in which R and R each represent an alkylene group,

an arylene group or an alkarylene group, and R can also represent agroup of the formula:

I! I i 5 ..c0R or -C-NR in which R has the same definition as R and inwhich the carbonyl moiety is attached directly to the polymericbackbone;

m and p each represent an integer having a value of 0 or 1; and

represents an onium salt group;

wherein R R", R and R", when taken separately, each represent a loweralkyl group;

R and R or R and R represent an imino group or, together with the carbonatom to which they are attached, represent the carbon atoms necessary tocomplete a 5- or 6-membered cycloalkyl or cycloalkenyl nucleus;

one of R and R, when taken with Z, represents a double bond in thecyclic nucleus formed by Z, in which case R or R respectively,represents I) an aryl group or (2) an amino radical; and

Z represents the nonmetallic atoms necessary to complete a 5-, 6- or7-membered heterocyclic nucleus;

said polymer further comprising at least 5 mole percent of a recurringunit having appended therefrom a water 5 solubilizing group.

12. A film unit as described in claim 11 wherein at least one of saidimage dye-providing materials is an oxichromic compound.

13. A film unit as described in claim 11 wherein at 60 least one of saidimage dye-providing materials is an oxichromic compound having theformula:

T (COUP) 1i 7 Ar s wherein:

(COUP) is a photographic color coupler linked to 25 the nitrogen atomthrough a carbon atom at the coupling position; Ar is an arylene group;J is selected from an amino group, a hydroxyl group or a group havingthe formula:

H -o-c-R wherein R is an alkyl or aryl group;

R is a hydrogen atom or a group having the formula:

0 ll -0-c-R wherein R" is as defined above; and

T is a silver halide developing agent or an oxidizable releasing group.

14. A film unit as described in claim ll wherein n and m are both 1 andL represents an iminium salt group.

15. A film unit as described in claim 11 wherein said polymer has amolecular weight greater than about 5000.

16. A film unit as described in claim 1 wherein said water-solublepolymer comprises at least 40 mole percent of a recurring unit havingthe following formula:

wherein:

R and R each represent a hydrogen atom or an alkyl group of about 1 to 6carbon atoms; R represents a hydrogen atom or a carboxy group; R and Reach represent an alkylene group having about 1 to 6 carbon atoms; eachR represents an alkyl group of about 1 to 10 carbon atoms; and X is ananion. 17. A film unit as described in claim 1 wherein saidwater-soluble polymer comprises at least 40 mole percent of a recurringunit having the following formula:

wherein:

R and R each represent a hydrogen atom or an alkyl group of about 1 to 6carbon atoms; R represents a hydrogen atom or a carboxy group; 5 R" andR each represent an alkylene group having about I to 6 carbon atoms;each R represents an alkyl group carbon atoms; and X is an anion. 18. Afilm unit as described in claim 1 wherein said water-soluble polymercomprises at least 40 mole percent of a recurring unit having thefollowing formula:

of about I to l0 l 3 set wherein:

R and R each represent a hydrogen atom or an alkyl group of about 1 to 6carbon atoms;

R represents a hydrogen atom or a carboxy group;

R is an alkarylene group having about 7 to 12 carbon atoms;

R represents an alkyl group of about 1 to 10 carbon atoms; and

X is an anion.

19. A receiving element comprising a support having therein at least onephotographic image-receiving layer and at least one layer containing awater soluble polymeric oxidant comprising at least 40 mole percent of arecurring unit having the formula:

eC-I I-R 28 R represents a hydrogen atom, an alkyl group, or

when taken together with R, R represents a carbonyl group; and

(NIOX) represent a stable free nitroxyl radical; said polymer furthercomprising at least 5 mole percent of a recurring unit having appendedtherefrom a water solubilizing group.

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTIONPATENT NO. 3,868,252 DATED February 5, 1975 |NVENTOR(5) Gerald A.Campbell; Hyman L. Cohen; Hans G. Ling |t H Ignazio S. Ponticello IS ceri ied that error appears in the above-identified atent t are herebycorrected as shown below: and hat Said Letters Patent In the claims:

Column 21, line 35, please omit colon following "backbone" and replacetherefor with a semicolon.

Column 2, line 20,

please insert L before the word "represents".

Column 26, beginning with line H2 in the formula, please delete thethree hyphens preceding and following the formula.

Signed and sealed this 15th day of July 1975.

(SEAL) Attest:

c. MARSHALL DANN RUTH c MASON. Commissioner of Patents Attesting Officer1 and Trademarks

1. A PHOTOGRAPHIC ELEMENT COMPRISING A SUPPORT HAVING THEREON AT LEASTONE PHOTOSENSITIVE SILVER SALT EMULSION LAYER AND AT LEAST ONE LAYERCONTAINING A WATER-SOLUBLE POLYMER COMPRISING AT LEAST 40 MOLE PERCENTOF A RECURRING UNIT HAVING THE FORMULA:
 2. A photographic element asdescribed in claim 1 wherein (NIOX) represents a heterocyclic nitroxylradical.
 3. A photographic element as described in claim 1 wherein n andm are both 1 and L represents an ammonium salt group.
 4. A photographicelement as described in claim 1 wherein said polymer has a molecularweight greater than about
 5000. 5. A photographic film unit comprising:a. a photosensitive element comprising a support having thereon aphotosensitive silver halide emulsion having associated therewith animage dye-providing compound; b. an image dye-receiving layer; and c.means for discharging an alkaline processing composition within saidfilm unit; said film unit containing a water-soluble polymer comprisingat least 40 mole percent of a recurring unit having the formula:
 6. Thefilm unit as described in claim 5 wherein said polymer is associatedwith said image-receiving layer.
 7. The film unit as described in claim5 wherein said polymer is contained in said alkaline processingcomposition.
 8. The film unit as described in claim 5 wherein (NIOX)represents a heterocyclic nitroxyl radical having the formula:
 9. Thefilm unit as described in claim 5 wherein (NIOX) represents aheterocyclic nitroxyl radical having the formula:
 10. The film unit asdescribed in claim 5 wherein (NIOX) represents a heterocyclic nitroxylradical having the formula:
 11. A photographic film unit comprising: a.a photosensitive element comprising a support having thereon a layercontaining a red-sensitive silver halide emulsion having associatedtherewith a cyan image dye-providing material, a layer containing agreen-sensitive silver halide emulsion having associated therewith amagenta image dye-providing material, and a layer containing ablue-sensitive silver halide emulsion having associated therewith ayellow image dye-providing material, b. an image dye-receiving layer;and c. means for discharging an alkaline processing composition withinsaid film unit; said film unit containing a water-soluble polymercomprising at least 40 mole percent of a recurring unit having theformula:
 12. A film unit as described in claim 11 wherein at least oneof said image dye-providing materials is an oxichromic compound.
 13. Afilm unit as described in claim 11 wherein at least one of said imagedye-providing materials is an oxichromic compound having the formula:14. A film unit as described in claim 11 wherein n and m are both 1 andL represents an iminium salt group.
 15. A film unit as described inclaim 11 wherein said polymer has a molecular weight greater than about5000.
 16. A film unit as described in claim 1 wherein said water-solublepolymer comprises at least 40 mole percent of a recurring unit havingthe following formula:
 17. A film unit as described in claim 1 whereinsaid water-soluble polymer comprises at least 40 mole percent of arecurring unit having the following formula:
 18. A film unit asdescribed in claim 1 wherein said water-soluble polymer comprises atleast 40 mole percent of a recurring unit having the following formula:19. A receiving element comprising a support having therein at least onephotographic image-receiving layer and at least one layer containing awater soluble polymeric oxidant comprising at least 40 mole percent of arecurring unit having the formula: